| 摘要 |
PROBLEM TO BE SOLVED: To execute data backup without using a CPU, a main memory unit or a system bus by judging which one of the main memory unit and a local memory memory access on a standard I/O bus is to be performed to through a bus controller. SOLUTION: By an I/O processor 13, transferred backup instruction data are read and write is performed in the local memory 14 through a local bus 11. After the write, in the case that backup conditions specified by the read backup instruction data are established, the bus controller 12 is controlled and an operation on the system bus 1 driven from the CPU 3 is retried in terms of a hardware. Then, by the I/O processor 13, in the retried state, whether the memory access on the standard I/O bus 2 is performed to the main memory unit 4 or performed to the local memory 14 is judged through the bus controller 12. |
